Step insert



FIG. 1 is a perspective view of the step insert showing a new ornamental design therefor, the opposite side perspective view being identical thereto;

FIG. 2 is a top plan view thereof;

FIG. 3 is a cross-sectional view taken in the direction of line 3--3 of FIG. 2; and,

FIG. 4 is a cross sectional view taken in the direction of line 4--4 of FIG. 2. 

The ornamental design for a step insert, as shown and described. 